Regular Hexagon Calculator

A regular hexagon is a six sided polygon with all sides equal and every interior angle equal to 120 degrees. It is the only regular polygon besides the square and triangle that tiles a flat plane with no gaps, which is why bees build honeycomb from it.

Area equals (3 times the square root of 3, divided by 2) times the side length squared. That constant is about 2.598076, so a side of 10 gives roughly 259.807621 square units. It equals six equilateral triangles of the same side.

The apothem is the perpendicular distance from the centre to the midpoint of any side. For a regular hexagon it equals the square root of 3 over 2 times the side, about 0.866025 times the side. For a side of 10 the apothem is 8.660254.

The long diagonal joins two opposite corners and passes through the centre, so it equals twice the side. The short diagonal skips one vertex and equals the square root of 3 times the side, about 1.732051 times the side.

A regular hexagon has six equal edges, so the perimeter is simply six times the side length. There is no rounding involved for whole side lengths, so a side of 6 gives a perimeter of exactly 36.

It is unit agnostic. Enter a side in centimetres, inches, metres, or any unit you like. Lengths keep that unit, and areas come out in the matching square unit. The tool never assumes a particular measurement system.

Calculations use full double precision and are then rounded to six decimal places for display. Irrational values such as the apothem and short diagonal are shown to that precision, so treat the last digits as approximate rather than exact.

No. Every formula here assumes all six sides and angles are equal. An irregular six sided shape needs its full set of vertex coordinates, so use a general polygon area tool that accepts a list of points instead.

No. The hexagon math runs entirely in your browser with plain JavaScript, so the side length you type never leaves your device and nothing is stored or uploaded.